1. Field of the Invention
The present invention relates to a recording apparatus having an adhesive roller for removing foreign objects from a recording medium, and the recording apparatus records information such as images or characters on the recording medium. Especially, the recording apparatus records information such as color images and characters with color toners of K (black), C (cyan), M (magenta) and Y (yellow).
2. Description of the Related Art
In a conventional recording apparatus of the above type, image recording is conducted when laser beams are irradiated from an optical head onto a recording medium fixed on a rotary drum used for recording. In this case, a toner sheet having a toner layer, which is formed on a permeable support, capable of conducting heat-transfer, and an image receiving sheet are used as a recording medium, and the toner sheet is heated according to image data to be recorded, so that a heated portion or a non-heated portion of the toner layer is transferred onto the image receiving sheet. In this way, an image is formed on the image receiving sheet.
Specifically, image recording is conducted as follows. A toner sheet is used, on which a heat-fusible, heat adhesive or sublimate coloring material layer (light-heat conversion+toner layer) is formed. At least at a recording position, the toner sheet is put on the image receiving sheet, that is, the toner sheet is closely contacted with the image receiving sheet, and the toner layer is heated according to image data by laser beams from a reverse side of the toner sheet or the image receiving sheet, so that a latent image is formed on the toner layer. After that, the toner sheet and the image receiving sheet are separated from each other. In this way, a portion of the toner layer, which has been exposed to laser beams, is transferred onto the image receiving layer, so that the image can be transferred onto the image receiving sheet.
First, explanation will be made referring to FIG. 15 which is a perspective view of a primary portion of the recording apparatus used for the present invention.
In FIG. 15, reference numeral 1 is an optical head having a plurality of lasers, and the respective lasers are turned on and off for modulation according to data to be recorded and the modulated laser beams are irradiated, and the optical head 1 is capable of moving in a direction of one dimension.
Reference numeral 2 is a rotary drum for recording on which a recording medium is attached, and this rotary drum is rotated at high speed.
Reference numeral 3 is a recording medium, the structure of which is different according to the use, that is, reference numeral 3 is a recording medium for CTP (computer to plate), DDCP (direct digital color proofer) or lease.
Reference numeral 4 is a movable stage or an auxiliary scanning stage, on which the optical head 1 is mounted, capable of moving on a rail in parallel with the recording medium 3 attached onto the rotary drum 2 for recording. While the movable stage 4 is moving, the recording medium 3 is irradiated with laser beams emitted from the optical head 1, so that an image can be recorded. The moving direction of the optical head 1 corresponds to the auxiliary scanning direction in the image formation, and the rotary direction of the rotary drum 2 for recording corresponds to the primary scanning direction.
Next, referring to FIG. 16, the structure of the recording medium 3 attached to this recording apparatus will be explained below. Also, referring to FIG. 17, the specific procedure of image recording will be explained below.
FIG. 16 is a view showing an image receiving sheet 31 and a toner sheet 32 composing the recording medium 3 shown in FIG. 15. In the actual recording process, image recording is conducted on the recording medium 3 by a heat transfer sheet composing the recording medium shown in FIG. 16. The toner sheet 32 is composed of xe2x80x9ca support, light-heat conversion layer and toner layerxe2x80x9d which are arranged in this order from the laser beam irradiating side. On the other hand, the image receiving layer 31 is composed of xe2x80x9can image receiving layer, cushion layer and supportxe2x80x9d which are arranged in this order from the toner sheet 32 side. The toner sheet 32 is put on the image receiving sheet 31 in such a manner that the toner layer of the toner sheet 32 is directed to the image receiving sheet 31 side, and laser beams are irradiated onto the toner sheet 32 and the image receiving sheet 31. Then, the irradiated toner layer is heated and transferred onto the image receiving layer.
The support of the toner sheet 32 shown in FIG. 16 is made of PET (polyethylene terephthalate), TAC (triacetyl cellulose) or PEN (polyethylene naphthalate) through which laser beams can be transmitted. For the light-heat conversion layer, carbon, black substance, infrared ray absorbing pigment and specific wave-length absorbing substance, which can effectively convert laser beam energy into heat, are used. On the toner sheet, there are provided toner sheets of K (black), C (cyan), M (magenta) and Y (yellow). In some cases, there are provided toner sheets of gold, silver, light-brown, gray, green and orange. Characteristics of heating and recording are different with respect to these toner sheets of various colors.
The image receiving layer of the image receiving sheet 31 receives toner to be transferred. The cushion layer functions to absorb steps when a plurality of toner layers are put on each other. In this connection, the above structure is different according to the use. The detail of the toner sheet and image receiving sheet to be used are described in Japanese Unexamined Patent Publication No. JP-A-4-296594, JP-A-4-327982 and JP-A-4-327983 which are applied by the present applicant.
FIG. 17 is a process drawing of recording which shows each recording process carried out for each color of K, C, M and Y. Each recording process is composed of a laminate process, a laser beam recording process in which recording is conducted by laser beams according to color data, and a process in which the toner sheet 32 is peeled off from the image receiving sheet 31.
Process (1)
The image receiving sheet is wound round the rotary drum 2 for recording (FIG. 17a).
Process (2)
First, in order to execute a process of color K, the toner sheet of color K is wound round the image receiving sheet (FIG. 17b).
Process (3)
When necessary, the toner sheet of color K is laminated on the image receiving sheet by the rotary roller, one portion of which is shown in the drawing (FIG. 17c).
Process (4)
Laser beams are irradiated according to image and character data of color K, so that recording is conducted (FIG. 17d).
Process (5)
The toner sheet of color K is peeled off from the image receiving sheet. In this way, the process of color K is completed (FIG. 17e).
Process (6)
In the same manner as that of the process of color K, the process of color C is executed. The toner sheet of color C is wound round the image receiving sheet.
Process (7)
Under certain circumstances, the toner sheet of color C is laminated.
Process (8)
Recording is conducted by laser beams according to data of color C.
Process (9)
Finally, the toner sheet of color C is peeled off from the image receiving sheet. In this way, the process of color C is completed.
Process (10)
Successively, in the same manner, the process of color M is executed. The toner sheet of color M is wound round the image receiving sheet.
Process (11)
Under certain circumstances, lamination is carried out.
Process (12)
Recording is conducted by laser beams according to data of color M.
Process (13)
The toner sheet of color M is peeled off from the image receiving sheet. In this way, the process of color M is completed.
Process (14)
Finally, in the same manner, the process of color Y is executed. The toner sheet of color Y is wound round the image receiving sheet.
Process (15)
Under certain circumstances, the toner sheet of color Y is laminated.
Process (16)
Recording is conducted by laser beams according to data of color Y.
Process (17)
Finally, the toner sheet of color Y is peeled off from the image receiving sheet. In this way, the process of color Y is completed.
Process (18)
Due to the foregoing, four colors of K, C, M and Y are appropriately put on the image receiving sheet, and a necessary color image can be formed (FIG. 17f).
In the above recording apparatus, color image recording of colors K, C, M and Y is conducted as follows. As shown in the arrangement view of FIG. 16, there is provided a recording medium 3 composed in such a manner that a toner sheet containing a heat-fusible, heat adhesive or sublimate toner is tightly put on the image receiving sheet. This recording medium 3 is fixed onto the rotary drum 2 for recording and irradiated with laser beams emitted from the optical head 1.
FIG. 18 is an overall arrangement view of the recording apparatus used in the present invention. Referring to FIG. 18, the summary of the recording apparatus is described below. In this connection, FIG. 18 is related to the application of the present applicant, the detail of which are described in Japanese Unexamined Patent Publication No. 07-290731.
In the drawing, reference numeral 30 is the recording apparatus used in the present invention. This recording apparatus 30 is provided for forming a full color image. This recording apparatus 30 includes: a supply section 32 for supplying a toner sheet 10 and an image receiving sheet 12; a rotary drum 34 used as a holding member for holding the toner sheet 10 at the image recording position and also used as a conveyance means for conveying the toner sheet 10; a photosensitive material fixing and releasing mechanism 36 arranged on the rotary drum 34; a laminate mechanism 38 arranged on an outer circumference of the rotary drum 34; an exposing means 40; a separating means 42; a sheet feed section 44; a laminate section 46; a fixing section 48; a separating section 50; a tray section 52; and a control section 84.
In the above recording apparatus 30, first, the image receiving sheet 12 is supplied from the supply section 32 onto the rotary drum 34 and fixed by the photosensitive material fixing and releasing mechanism 36. Next, the toner sheet 10 is supplied onto the rotary drum 34 from the photosensitive material supply section 32 and laminated on the image receiving sheet 12 by the laminate mechanism 38.
After that, the toner sheet 10 is exposed to and heated by the laser beams sent from the optical head 24 which is controlled by an image signal sent from the control section 84. In this way, a latent image is formed on the toner sheet 10.
Successively, the toner sheet 10 is peeled off from the image receiving sheet 12, which is fixed onto the rotary drum 34, by the separating mechanism 42. The latent image on the toner sheet 10 is transferred onto the image receiving sheet 12 and developed. In this way, an image is formed on the image receiving sheet 12.
The above operation is repeated with respect to three to four colors, so that a color image is formed on the image receiving sheet 12. After the formation of the color image on the image receiving sheet 12, this image receiving sheet 12 and a main sheet 14, which has been supplied from the sheet supply section 44, are laminated in the laminate section 46. Then, the image receiving layer 16 on the image receiving sheet 12 is optically fixed by the fixing section 48 and peeled off by the separating section 50. The main sheet on which the full color image is formed is discharged onto the tray 52a, and the thus used image receiving sheet 12 is discharged onto a stacker 52b for used sheets. In this way, a hard copy of the full color image can be obtained.
The supply section 32 includes: a station 53 for holding a roll-shaped image receiving sheet 12 and a plurality of roller-shaped toner sheets 10 such standard toner sheets of Y, M, C and K or specific color sheets used in the field of printing; a pair of drawing rollers 54 for drawing the roll-shaped toner sheet 10 and the image receiving sheet 12; a cutter 55 for cutting the toner sheets 10 and others drawn out from the station 53 by the drawing roller 54 by a predetermined length; a pair of rollers 56 for conveying the toner sheet 10 and others when they are interposed between the rollers 56; and a guide 57 for guiding the toner sheet and others and also guiding ends of the toner sheet and others to the fixing and releasing mechanism 36 attached onto the rotary drum 34.
First, the image receiving sheet 12 is supplied to the rotary drum 34. A leading end of the image receiving sheet 12 is fixed by a clamp of the fixing and releasing mechanism 36. Then, the image receiving sheet 12 is wound on an outer circumference of the rotary drum 34 by the rotation of the rotary drum 34 in the direction of an arrow shown at the center of the drawing. A trailing end of the image receiving sheet 12 is also fixed by a clamp of the fixing and releasing mechanism 36. In this case, it is preferable that at least one of the leading end fixing section and the trailing end fixing section of the fixing and releasing means 36 for fixing and releasing the toner sheet 10 is capable of moving on the outer circumference of the rotary drum 34 so that the toner sheets 10 of various lengths can be fixed by the fixing section.
Next, the toner sheet 10 conveyed from the supply section 32 is laminated and wound on the image receiving sheet 12 which has been wound on the outer circumference of the rotary drum 34. The toner sheet 10 is laminated on the image receiving sheet 12 by a laminate mechanism 38 including: a laminate roller 58 into which a heater may be incorporated; an arm 59 for rotating the laminate roller 58 round a fulcrum 59a so that the laminate roller 58 can be contacted with the outer circumference of the rotary drum 34; and a pushing means for pushing the laminate roller 58 against the outer circumference of the drum by a predetermined pushing force.
The image receiving sheet and the toner sheet may be fixed onto the rotary drum by a vacuum suction mechanism or an electrostatic suction mechanism.
After the image receiving sheet 12 and the toner sheet 10 have been laminated and fixed onto the rotary drum 34, the toner sheet 10 is exposed to and heated by optical beam L emitted from the exposure means 40 from the reverse side (the support 18 side), so that a latent image can be formed on the toner layer 22.
The exposure means 40 includes: a modulation means; an optical head 24 composed of a light source for emitting a beam of light of high energy density and an image formation lens for adjusting a diameter of a light beam spot; and an auxiliary scanning means 61 for conducting auxiliary scanning by moving the beam of light in the auxiliary scanning direction when the optical head 24 is moved in the axial direction of the rotary drum 34. In this case, the auxiliary scanning direction 61 corresponds to the moving stage 4 shown in FIG. 15.
On the other hand, the primary scanning of a beam of light conducted on the toner sheet 10 is made by the rotation of the rotary drum 34 in the direction of arrow y, that is, the conveyance of the toner sheet 10 (the image receiving sheet 12) is made by the rotation of the rotary drum 34 in the direction of arrow y. In the recording apparatus 30 shown in the drawing, the toner sheet 10 is two-dimensionally scanned by light beam L in the same manner as that of the drum scanner.
In the above conventional recording apparatus, an adhesive roller is used in the recording medium conveyance system (A), and an adhesive roller is used in the recording section (B).
The reason why (A) the adhesive roller is used in the recording medium conveyance system is to prevent the formation of a defective image in the main sheet transfer process conducted successively, by removing foreign objects described in the following items (1) to (3). That is, the foreign objects are removed as follows.
(1) Foreign objects adhering to a recording medium are removed.
(2) Foreign objects adhering to a recording medium in a recording medium path in the process of conveyance are removed.
(3) When a continuous recording medium is cut by a cutter section, chips are generated from the recording sheet and adhering to the recording medium. Thus generated chips are removed.
FIG. 1 is a view showing a case described in the above item (1).
The devices illustrated in FIG. 1 correspond to the station 53 for holding a roller-shaped image receiving sheet 12 and a plurality of roller-shaped toner sheets 10 illustrated in FIG. 18 and also correspond to a pair of drawing rollers 54 for drawing the roller-shaped toner sheet 10 the image receiving sheet 12 illustrated in FIG. 18. In the above structure, at least one of the upper and the lower conveyance roller is an adhesive rubber roller. Accordingly, foreign objects adhering onto the recording medium conveyed in the direction of an arrow are removed while they are passing through between the upper and the lower conveyance roller, at least one of which is an adhesive roller.
FIG. 2 is a view showing a case described in the above item (2) in which foreign objects adhering to a recording medium in the recording medium conveyance path in the process of conveyance are removed.
In this case, it possible to consider the following three cases in which foreign objects adhering to the conveyance guide plate are adhering to the recording medium.
1) While a recording medium is being conveyed, it is bent. Due to the foregoing, the recording medium comes into contact with the conveyance guide plate, and foreign objects on the conveyance guide plate adhere to the recording medium.
2) By an electrostatic force generated by the recording medium which has been electrically charged, foreign objects on the conveyance guide plate are attracted by the recording medium, so that the foreign objects adheres to the recording medium.
3) A recording medium is attracted to the conveyance guide plate by the electrostatic force generated by the electrical charging of the recording medium, so that the foreign objects on the conveyance guide adheres to the recording medium.
Referring to FIG. 18, the above circumstances occur in the regions of the guide 57 to guide the toner sheet 10 onto the rotary drum 34 and the conveyance roller 56.
Therefore, at least one of the upper 1 and the lower conveyance roller 2 used for the conveyance system is composed of an adhesive roller. Accordingly, foreign objects adhering to the recording medium conveyed in the direction of the arrow are removed while the recording medium is being conveyed between the upper and the lower conveyance roller which are respectively composed of adhesive rollers.
According to the above item (3), when a continuous recording medium is cut by the cutter section into a sheet-shape, chips are generated from the recording sheet and adheres to the recording medium.
FIG. 3 is a view showing a case in which the thus attached chips are removed from the recording medium. The recording medium is conveyed by the upper and the lower conveyance roller before it is cut. Since at least one of the conveyance rollers is an adhesive rubber roller as shown in FIG. 2, foreign objects are removed from the recording medium before the recording medium is cut by a rotary blade. While the recording medium is being cut by the rotary blade, chips are generated from the recording medium and attached to the recording medium. FIG. 3 shows these circumstances. Referring to FIG. 18, the above circumstances occur in the regions of the cutter 55 to cut the toner sheet 10, which has been drawn out from the station 53 by the drawing roller 54, and the pair of conveyance rollers 56 to convey the toner sheet 10 and others. Therefore, at least one of the upper and the lower conveyance roller used after cutting is an adhesive rubber roller. Accordingly, foreign objects adhering to the recording medium conveyed in the direction of the arrow are removed while the recording medium is passing between the upper and the lower conveyance roller. The reason why the adhesive roller is used in the recording section (B) described before is that the foreign objects described in items (1) to (3) are removed so that the occurrence of a defective image can be prevented in the next main sheet transfer process. The detail are described as follows.
(1) Foreign objects adhering to the recording drum are removed.
(2) While the recording medium is being conveyed to the recording drum, or while the recording medium is being conveyed out from the recording drum, foreign objects attaching onto a surface of the recording medium are removed.
(3) Foreign objects adhering onto a surface of the recording medium which has been set on the recording drum are removed.
FIG. 3 shows a case of the above item (1) in which foreign objects adhering to the recording drum are removed.
As shown in the drawing, foreign objects attached onto the recording drum rotating in the direction of the arrow are removed by the adhesive roller, which is arranged in such a manner that it comes into contact with the recording drum, while the recording medium is passing through the adhesive roller.
FIG. 5 shows a case of the above item (2) in which while the recording medium is being conveyed to the recording drum, foreign objects adhering onto a surface of the recording medium are removed. In the drawing, foreign objects attached onto the recording medium conveyed in the direction of the arrow are removed by the adhesive roller which is arranged in such a manner that it comes into contact with the recording drum while the recording medium is passing through the adhesive roller.
FIGS. 6 and 7 show a case of the above item (2) in which while the recording medium is being conveyed out from the recording drum, foreign objects adhering onto a surface of the recording medium are removed. FIG. 6 is a view showing a case in which the recording medium is conveyed to left with respect to the rotary drum, and FIG. 7 is a view showing a case in which the recording medium is conveyed to right with respect to the rotary drum. In both drawings, foreign objects adhering onto the recording medium conveyed in the direction of the arrow are removed by the adhesive roller coming into contact with the recording drum while the recording medium is passing through the adhesive roller.
FIGS. 8 and 9 are views showing a case of the above item (3) in which foreign objects attached onto the recording medium during recording are removed. FIG. 8 is a view showing a case in which one sheet of recording medium (for example, one sheet of image receiving sheet) is conveyed on the rotary drum rotating in the direction of the arrow. FIG. 9 is a view showing a case in which two sheets of recording mediums (for example, one sheet of image receiving sheet and one sheet of toner sheet) are conveyed on the rotary drum rotating in the direction of the arrow. In both drawings, for example, foreign objects adhering onto the recording medium on the recording drum rotating in the direction of the arrow are removed by the adhesive roller while the recording medium is passing through the adhesive roller.
Referring to FIG. 18, the above circumstances occur in the region of the rotary drum 34 and also in the region before and after the rotary drum 34.
However, adhesive forces of the adhesive rubber rollers used in the above conveyance system (shown in FIGS. 1 to 3) and the recording section (shown in FIGS. 4 to 9) tend to decrease by a lapse of time. Therefore, when about 2 to 3 months have passed after the adhesive rubber rollers were manufactured, capacities of the adhesive rubber rollers to remove foreign objects from the recording mediums are deteriorated. As a result, images are not recorded in some portions of the recording medium, that is, defective images are formed.
The present invention has been accomplished to solve the above problems. It is an object of the present invention to provide an image recording apparatus characterized in that: foreign objects adhering onto a recording medium can be removed over a long period of time by using an adhesive rubber roller, the adhesive force of rubber of which is seldom changed with time, so that images having no defects can be obtained over a long period of time; and it is unnecessary to conduct maintenance on the recording apparatus over a long period of time.
In order to accomplish the above object, the invention described in claim 1 provides a recording apparatus comprising: a recording medium supply section; a recording medium conveyance section; a recording medium cutting section; and a recording section, wherein an adhesive rubber roller containing TiOx (titanium oxide) is used in at least one of said sections.
The invention described in a second aspect provides a recording apparatus comprising: a recording medium supply section; a recording medium conveyance section; a recording medium cutting section; and a recording section, wherein an adhesive rubber roller containing TiOx (titanium oxide) and not containing Ba (barium) is used in at least one of said sections.
The invention described in a third aspect provides a recording apparatus comprising: a recording medium supply section; a recording medium conveyance section; a recording medium cutting section; and a recording section, wherein an adhesive rubber roller containing hydrocarbon compound having a functional group of Cxe2x80x94O or Sixe2x80x94O is used in at least one of said sections.
The invention described in a fourth aspect provides a recording apparatus comprising: a recording medium supply section; a recording medium conveyance section; a recording medium cutting section; and a recording section, wherein an adhesive rubber roller containing TiOx (titanium oxide) and hydrocarbon compound having a functional group of Cxe2x80x94O or Sixe2x80x94O is used in at least one of said sections.
The invention described in a fifth aspect provides a recording apparatus comprising: a recording medium supply section; a recording medium conveyance section; a recording medium cutting section; and a recording section, wherein an adhesive rubber roller containing TiOx (titanium oxide) and hydrocarbon compound having a functional group of Cxe2x80x94O or Sixe2x80x94O and not containing Ba (barium) is used in at least one of said sections.
The invention described in a sixth aspect provides a method of removing foreign objects applied to a recording apparatus having a recording medium supply section, a recording medium conveyance section, a recording medium cutting section and a recording section, comprising the step of removing foreign objects from a surface of the recording medium or the inside of the recording apparatus when an adhesive rubber roller containing TiOx (titanium oxide) is used in at least one of said sections.
The invention described in a seventh aspect provides a method of removing foreign objects applied to a recording apparatus having a recording medium supply section, a recording medium conveyance section, a recording medium cutting section and a recording section, comprising the step of removing foreign objects from a surface of the recording medium or the inside of the recording apparatus when an adhesive rubber roller containing TiOx (titanium oxide) and not containing Ba (barium) is used in at least one of said sections.
The invention described in a eighth aspect provides a method of removing foreign objects applied to a recording apparatus having a recording medium supply section, a recording medium conveyance section, a recording medium cutting section and a recording section, comprising the step of removing foreign objects from a surface of the recording medium or the inside of the recording apparatus when an adhesive rubber roller containing hydrocarbon compound having a functional group of Cxe2x80x94O or Sixe2x80x94O is used in at least one of said sections.
The invention described in a ninth aspect provides a method of removing foreign objects applied to a recording apparatus having a recording medium supply section, a recording medium conveyance section, a recording medium cutting section and a recording section, comprising the step of removing foreign objects from a surface of the recording medium or the inside of the recording apparatus when an adhesive rubber roller containing TiOx (titanium oxide) and hydrocarbon compound having a functional group of Cxe2x80x94O or Sixe2x80x94O is used in at least one of said sections.
The invention described in a tenth aspect provides a method of removing foreign objects applied to a recording apparatus having a recording medium supply section, a recording medium conveyance section, a recording medium cutting section and a recording section, comprising the step of removing foreign objects from a surface of the recording medium or the inside of the recording apparatus when an adhesive rubber roller containing TiOx (titanium oxide) and hydrocarbon compound having a functional group of Cxe2x80x94O or Sixe2x80x94O and not containing Ba (barium) is used in at least one of said sections.
The invention described in a eleventh aspect provides a recording apparatus according to one of claims 1 to 5, wherein high speed scanning (primary scanning) is conducted by the rotation of the rotary drum and low speed scanning (auxiliary scanning) is conducted by the movement of an optical head in the axial direction of the rotary drum.
The invention described in a twelfth aspect provides a recording apparatus according to one of claims 6 to 10, wherein high speed scanning (primary scanning) is conducted by the rotation of a rotary drum and low speed scanning (auxiliary scanning) is conducted by the movement of an optical head in the axial direction of the rotary drum.